What Causes Morning Sickness
Morning sickness is a common symptom of early pregnancy. Here we explain everything you need to know about morning sickness - including when you can expect it to pass!
Let’s clarify from the outset that ‘morning sickness’ (also known as Nausea and Vomiting of Pregnancy) is NOT restricted to the a.m. Many newly pregnant women are rudely shocked when nausea strikes them not only upon waking, but also after lunch, during the train commute home from work, when cooking dinner or, indeed, 24/7.
Most pregnant women experience some level of unsettling nausea during the first trimester, with about 50 percent enduring vomiting or retching bouts.
Women pregnant with twins or triplets can have more pronounced symptoms.
There is no evidence that the sex of the baby has an impact on the severity of morning sickness.
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What is Hyperemesis Gravidarum?
A very unlucky few pregnant women – between 0.5 and 3 percent – develop the very serious condition, Hyperemesis Gravidarum (HG). HG sufferers are barely able to hold down any food or liquid and are thus at risk of dehydration, electrolyte imbalances, even malnutrition.
Where morning sickness sufferers are able to maintain their weight, experience only episodic vomiting, and often feel better during the second trimester, HG-afflicted women have their lives profoundly disrupted (sometimes for the entire pregnancy) and are often hospitalised.
As with morning sickness, the exact reasons why HG develops are unknown. The long-standing assumption (unfortunately still prevalent amongst some medical care providers), that the condition is psychosomatic, is incorrect.
What causes morning sickness?
There is no clear cause for morning sickness. Studies have suggested a complex symphony of increased levels of estrogen and progesterone, low blood sugar and low blood pressure bring on nausea.
That the risk of miscarriage is reduced in morning sickness sufferers also indicates an evolutionary protective function: mothers’ increased sensitivity to food and smells ensures babies aren’t exposed to plant-based toxins.
While it is nearly impossible to predict whether a woman will develop HG in her first pregnancy, those with a history of migraines may be more susceptible. There may also be a genetic component, with mothers, daughters and sisters frequently suffering similarly severe symptoms. Many women who suffer morning sickness in their first pregnancy, will do so again during subsequent pregnancies.